The effect of complete tenotomy on blood flow to the anterior segment of the canine eye.

The relative importance of the anterior ciliary arteries to blood flow to the anterior segment and the quadrant distribution of blood to the iris, ciliary body, and ciliary processes were determined in canines with the use of 15 +/- 3 mum 103Ru microspheres with the reference blood flow method. Recti muscles were isolated in both eyes. Then with one eye serving as a sham-operated control, anterior ciliary artery blood flow was disrupted by recti tenotomy immediately prior to microsphere injection. Tenotomy resulted in a significant decrease in blood flow to the anterior segment (0.14 +/- 0.03 ml/min/gm vs. 0.26 +/- 0.05 in the untenotomized control) and to the unit iris, ciliary body and ciliary processes (I, CB, CP) (0.92 +/- 0.16 ml/min/gm vs. 1.44 +/- 0.22 in the untenotomized control). Blood flow values for the anterior segment and the unit I, CB, CP in the tenotomized eye were 50% to 60% of those of the control eyes, indicating that the majority of blood flow to the canine anterior segment is not disrupted by complete tenotomy. In the control eye, blood flow values for the medial quadrant of the unit I, CB, CP were significantly higher (p < 0.05) than those of the inferior or superior quadrants. Blood flow values for all quadrants in tenotomized eyes were 55% to 70% of those for control eyes. Therefore the anterior ciliary arteries do not contribute the majority of blood flow to the canine anterior segment.